The algolytic strain SLW6 was screened from water and soil samples from different sources,which has the effect of algicidal activity on Anabaena flos aquatica. The morphological characteristics, physiological and biochemical identification and 16S rDNA sequence analysis of strain SLW6 were carried out. The effects of algaeclytic bacteria on algaeclytic effect of strain SLW6 in different culture periods and pH conditions were studied. The pattern of dissolving Anabaena flos aquae by the strain was explored. The results showed that: strain SLW6 was a Gram-negative bacterium, negative in V-P test, gelatin liquefaction test and methyl red test, while positive in hydrogen peroxide test and nitrate reduction test; the homology between SLW6 strain and Alcaligenes faecalis (NR113606.1) strain was 99.65%; combined with morphological characteristics, physiological and biochemical identification and 16S rDNA sequence analysis, it was preliminarily determined that the algae lytic strain SLW6 was an alkali producing bacterium (GenBank accession number, OP363821).Ultrasound assisted hot ethanol extraction of the chlorophyll a, determination of chlorophyll a content by spectrophotometry, and calculation of the algal dissolution rate based on the change of chlorophyll a content, the results showed that SLW6 had the best algae dissolving effect when it was in the logarithmic phase, and the algae dissolving rate was 89.45%; when pH was 7, the effect of algae dissolution was better, and the algae dissolution rate was 47.03%; the mode of action of alginolytic bacteria SLW6 on Anabaena flos aquatica was that the direct alginolytic activity is dominant and the indirect alginolytic activity is secondary.